This invention relates generally to improvements in dental devices and procedures used in the formation of custom fitted dental prostheses, such as crowns, bridges, veneers, and the like. More particularly, this invention relates to improvements in dental impression or bite registration trays which incorporate relatively simple and easily manipulated means for indicating patient bite angle, thereby permitting formation of the prosthesis in accordance with patient bite angle.
Dental prostheses such as crowns, bridges, veneers, etc. and related dental procedures are well known in the art for restoring damaged or missing teeth within the mouth of a patient. In general terms, the area to be restored is initially prepared by the dentist, such as by reducing a damaged tooth by drilling and shaping procedures to form a suitable base adapted to receive and support a prosthetic crown. The prepared area including adjacent and opposing tooth and gum structures is then replicated by means of a dental impression defined typically by a curable vinyl elastomer or the like carried on a suitably shaped impression tray which is placed into the patient's mouth for the duration of a short cure cycle. The dental impression is then used to form the appropriate mold or molds from which the desired dental prosthesis is formed, normally from a castable gold alloy or the like. Other types of dental prostheses may require an imprint of the patient's bite registration in lieu of a dental impression.
The dental impression or bite imprint is commonly fitted into a dental articulator in the course of producing the requisite mold or molds for the final prosthesis. However, in accordance with standard dental laboratory procedures, the dental articulator is oriented horizontally to correspondingly reproduce a horizontal patient bite line or angle. Unfortunately, the actual bite angle in many patients deviates from a horizontal plane. As a result, the prosthesis is shaped for precision custom fit according to a horizontal patient bite line which does not in fact exist. When the dentist attempts to place the prosthesis into the patient's mouth, an improper or unsatisfactory fit is recognized. Since most bite angle deviations are relatively small, the dentist normally tries to remedy the prosthesis misfit by trial and error grinding of the prosthesis. This approach can be extremely costly to the dentist by substantially increasing the time needed for proper prosthesis fit and placement. Moreover, and more importantly, trial and error attempts to reshape the prosthesis often result in a poor fit and resultant poor service life and patient dissatisfaction.
In the past, dental appliances have been proposed particularly in the field of orthodontics for use in measuring the patient bite line or angle. However, such appliances have been relatively costly and difficult to use, and further have not provided a bite angle indication which can be satisfactorily communicated to and reproduced at a dental laboratory located typically at a different facility. Accordingly, in spite of the aforementioned problems attributable to bite angle variations, the general dental practice has been to ignore the problem or otherwise accommodate bite angle deviations by estimation and/or trial and error procedures.
There exists, therefore, a significant need for further improvements in dental appliances and methods, particularly with respect to the provision of relatively simple yet accurate means for indicating patient bite angle. The present invention fulfills these needs and provides further related advantages.